It was familiar and troubling, another Chiefs starting quarterback being helped off the field because of an injury. And there was Kansas City, turning to Tyler Thigpen again as the replacement. Matt Cassel was supposed to be the answer. The Chiefs traded for him in March, signed him to a big contract in June, and hoped he&rsquo;d emerge as something the team didn&rsquo;t have last year: a healthy, reliable quarterback with a bright future.